1. Field of the Invention
The present invention relates to a wireless power transfer system for a plurality of apparatuses, a control method of the wireless power transfer system, a wireless power transmitting apparatus, a control method of the wireless power transmitting apparatus, and a storage medium.
2. Description of the Related Art
In recent years, apparatuses such as cellular phones which use rechargeable batteries are popularly used. A system for charging a rechargeable battery is configured by a primary-side apparatus which transmits power to the rechargeable battery, and a secondary-side apparatus which receives power.
In such a charging system, a technique for displaying a charging state of a rechargeable battery on the primary side is available (Japanese Patent Laid-Open No. 8-019189). Also, a technique for displaying a charging state of a rechargeable battery on a secondary-side apparatus is available (Japanese Patent Laid-Open No. 7-241045).
Furthermore, a technique for transferring power to a plurality of apparatuses using electromagnetic induction or electromagnetic resonance is available (Japanese Patent Laid-Open No. 2008-017592, U.S. Patent Application Publication No. 2009/0140690). Moreover, a wireless power transfer technique, which communicates so as to supply power to a secondary-side apparatus that uses a different voltage or current, is available (Japanese Patent Laid-Open No. 6-133476).
However, in a wireless charging system which can wirelessly charge a plurality of secondary-side apparatuses, the power transmitting capability of a primary-side apparatus has an upper limit specified by that wireless charging system.
On the other hand, in the wireless charging system, a restriction about the position of the secondary-side apparatus during charge is relatively moderate because the primary-side apparatus and secondary-side apparatus need not be connected. For this reason, there is a case that a predetermined number or more of secondary-side apparatuses are located within a wirelessly chargeable region and not charged wirelessly over the power transmitting capability of the primary-side apparatus.
In this case, the following phenomena may occur. That is, the charging times of the respective secondary-side apparatuses may be prolonged, and a specific secondary-side apparatus may not be charged. However, with the conventional technique, since the user does not receive any information indicating that such phenomena have occurred, he or she cannot judge whether or not the phenomena have occurred due to a trouble of the primary-side apparatus or secondary-side apparatus.
When a secondary-side apparatus of a electromagnetic resonance system is set to be closer to a primary-side apparatus of an electromagnetic induction system, since their wireless power transfer systems are different, the primary-side apparatus never transmits power to the secondary-side apparatus. The user is not able to judge whether a specific secondary-side apparatus cannot receive power due to a different wireless power transfer system or it cannot receive power since the power transmitting capability of the primary-side apparatus does not wirelessly charge that apparatus.
The present invention provides, in consideration of the above problems, a technique which allows the user to recognize the reasons why a charging time delay phenomenon and a non-charging phenomenon have occurred at the time of wireless power transfer.